#include "bullet.h"
#include"config.h"
Bullet::Bullet()
{
//加载子弹资源
    m_Bullet.load(BULLET_PATH);
//子弹坐标
    m_X=GAME_WIDTH *0.5-m_Bullet.width()*0.5;
     m_Y=GAME_HEIGHT;

     //子弹状态  默认空闲
     m_Free=true;

     //子弹速度
     m_Speed= BULLET_SPEED;

     //子弹边框
     m_Rect.setWidth(m_Bullet.width());
     m_Rect.setHeight(m_Bullet.height());
     m_Rect.moveTo(m_X,m_Y);


}
void Bullet:: updatePosition(){
   //空闲状态下的子弹，不需要计算坐标
    if(m_Free){
        return;
    }
    //子弹向上移动
    m_Y-=m_Speed;
    m_Rect.moveTo(m_X,m_Y);
    if(m_Y<0-m_Rect.height()){
        //子弹位置超出屏幕，重新变为空闲状态
        m_Free=true;
    }
}
